The TIPTOP study will test the following two hypotheses:
- Compound-by-compound chemical water quality assessment based on concentrations of target-analyzed pollutants is toxicologically and ecologically less relevant and thereby less protective than risk assessment based on bioassay responses to the complex mixture of pollutants as a whole;
- A combination of time-integrative passive sampling followed by toxicity profiling is a more cost-effective, alternative to determine if “good surface water chemical status” is reached than the currently applied chemical analysis of a continuously expanding suite of individual substances.
To test these hypotheses, TIPTOP will evaluate a combined strategy of suitable passive sampling and toxicity profiling techniques for the assessment of adverse toxic effects of chemicals on ecological quality of surface waters. The following objectives have been set for this TIPTOP study:
1) Perform passive sampling at six well-characterized WFD locations in the Dutch delta and in effluents from two urban wastewater treatment plants (WWTPs) with different industrial contributions to the waste water influent;
2) Determine toxicity profiles for the sample extracts in a battery of bioassays consisting of seven mechanistic in vitro bioassays and six small-volume in vivo bioassays representing four trophic levels;
3) Collect and determine concentrations of pollutants in passive samplers and water from the sampling sites;
4) Make ecologically relevant interpretations of the available chemical concentrations analyses and the observed toxicity profiles (including benchmarking to a WWTP toxicity profile) and compare these with the observed ecological status;
5) Critically evaluate the applied strategy in line with results of similar previous approaches (published and unpublished), and indicate necessary improvements/validity tests;
6) Propose a cost-effective and technically feasible protocol for time-integrative passive sampling combined with toxicity profiling, together with a framework for assessing acceptability.
T. Hamers, J. Legradi, N. Zwart, F. Smedes, J. de Weert, E-J. van den Brandhof, D. van de Meent, D. de Zwaer, Executive summary "Time-Integrative Passive sampling combined with Toxicity Profiling (TIPTOP): an effect-based strategy for cost-effective chemical water quality assessment", May 2016
Time Integrative Passive sampling combined with Toxicity Profiling (TIPTOP): an effect based strategy for cost-effective chemical water quality assessment, presented at the 16th Cefic-LRI Annual Workshop 2014